The role of particular neurons in a region of monkeys' brains known to be important for object recognition is more clearly established by a study appearing online in Nature (Vol. 442, No. 7101, July 27, 2006).
The research shows that artificially activating these nerve cells biases the monkey's choices in face categorization tasks.
Hossein Esteky and colleagues studied face perception in two adult monkeys (Macaca mulatta) trained to complete a task in which they had to judge whether noisy visual images, some of which were faces, belonged to "face" or "non-face" categories. The researchers electrically stimulated clusters of neurons in the inferotemporal cortex that were shown to respond selectively to faces, with the result that the decisions made by the monkeys were biased towards the face category. The authors report that this effect depended upon the size of the brain area stimulated and the exact time at which stimulation occurred.
The precise role of face-selective neurons in behaviour has been under debate. The authors suggest that their research, at very high spatial resolution, establishes a causal link between the activity of face-selective neurons and face perception.
Hossein Esteky (Institute for Studies in Theoretical Physics and Mathematics, Tehran, Iran)
Abstract available online.
(C) Nature press release.
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